Neuroscientists lack any credible explanation for human memory. Neuroscientists cannot credibly answer any of these questions:
- How is a human able to ever instantly learn all of the many different things that humans can learn?
- How is a human ever able to retain memories for decades, something that should be impossible from units such as synapses, which are built from proteins which have average lifetimes of only a few weeks or less?
- How could a brain ever store a memory when nothing in a brain seems to bear any resemblance to some component capable of writing information?
- How could a brain ever read a memory when nothing in a brain seems to bear any resemblance to some component capable of reading memory information?
- How could there possibly be memories stored in brains, when there has been the most careful microscopic examination of so many thousands of brains of very recently deceased people, and the most careful microscopic examination of so many thousands of chunks of brain tissue from living people, without any trace of learned information ever being discovered from such examination?
- How could there possibly be memories stored in brains, when no one has ever credibly discussed any encoding system whereby episodic memories or learned knowledge could be converted to neuron states or synapse states?
- How could a human ever instantly remember lots of relevant facts about a person, place or event as soon as he hears the name of such a person, place or event, something seemingly impossible using a brain lacking any of the things that enable fast recall of stored information (addresses, indexes and sorting)?
When writing papers trying to persuade us that they have some understanding of such matters, neuroscientists engage in various types of bluffs, vacuous hand-waving and misleading tricks. They include these:
- The most common trick is to abundantly cite junk science studies. So a neuroscientist might write some paper filled with mentions of experimental neuroscience papers. If you actually examine these papers, you will find they are almost all very low-quality papers guilty of very bad examples of Questionable Research Practices, such as the use of way-too-small study group sizes.
- Another trick used by empty-handed neuroscientists discussing memory is the trick I can call concurrent process description. It works like this: using jargon-laden language, a neuroscientist will describe some type of biochemistry activity or electrical activity going on when a person learns or remember, typically some type of activity that is constantly occurring in the brain. An attempt will be made to insinuate that such activity explains something going on during learning or recall. So we will read statements such as "While you are learning your school lessons, neurotransmitters are traveling across synapses, and new proteins are being synthesized that may strengthen synapses." The fallacy is that such things are occurring in the brain constantly, regardless of whether you are learning anything or forming any new memory or recalling anything. You do not explain things that occur only at some times by referring to types of events that occur constantly in the brain, even when learning and recall is not occurring.
- The writer may take a kind of approach we may call the "neural miscellany" approach. The approach consists of trying to mention a large variety of neuroscience terms referring to different types of structures or cells in brains or different anatomical parts in the brain or different chemical processes in brains, and so forth. These mentions never add up to a decent explanation for any part of memory, but by given these jargon-laden mentions, some impression of understanding may be created.
- Vague claims are made that memories are "processed" or "handled" by some particular part of the brain. Typically some very specific reference will be made to some particular fraction of the brain's anatomy, or some particular structures in the brain. No one should be impressed or persuaded by such claims, which typically are completely vague about what this alleged processing was. An example is this claim in Alberini's paper (discussed below): "These memories are processed by the medial temporal lobe-dependent memory system, which consists of the hippocampal region (CA fields, dentate gyrus, and subicular complex) and the adjacent perirhinal, entorhinal, and parahippocampal cortices."
- To try to create some greater impression of substance or knowledge, references to anatomy or biochemistry will be mixed up with psychology references to details of the phenomena of memory, such as the difference between explicit memory and implicit memory, the difference between episodic memory and muscle memory, the difference between learning and recall, and the difference between short-term memory and long-term memory. Such psychology references do not involve any neural explanation of memory, but by using them a writer will help to create more of an impression of knowledge on the topic of memory.
- Another technique is to engage in what we can call "contribution" hand-waving. The technique involves mentioning various parts of the brain or chemicals in the brain, and vaguely claiming that such things "contribute" to memory. No actual explanation is going on when such hand-waving occurs. Claims about hundreds of possible "contributions" may be made without explaining how something occurs. Contribution is not causation. For example, my eyeglasses contribute to the overall process by which I see things and remember things I have seen. But my eyeglasses do not do anything to explain the mystery of memory creation or learning.
We see an example of such "contribution" hand-waving in the recent paper "Not just neurons: The diverse cellular landscape of learning and memory" by neuroscientist Christina M. Alberini. Alberini has no credible tale to tell to explain how there could occur any of the phenomena of memory. What she mainly does is to make unwarranted or not-very-relevant claims about this or that thing "contributing" to memory or learning.
Near the beginning of the paper, we have a concurrent process description by Alberini, who mentions "gene expression" and "chromatin regulation" while discussing learning. Gene expression and chromatin regulation are constantly occurring events in the brain, and there is no evidence they occur more often or differently when a person learns or recalls.
Alberini makes the statement below, which makes unwarranted boasts, and finally ends with a confession of ignorance:
" These memories are processed by the medial temporal lobe-dependent memory system, which consists of the hippocampal region (CA fields, dentate gyrus, and subicular complex) and the adjacent perirhinal, entorhinal, and parahippocampal cortices. This system can store memories of single episodic experiences for as long as we live—a process of very long-term storage that still lacks an understanding of its biological underpinnings. The implicit memory system, on the other hand, stores and recalls unconscious and automatic memories. These include habits, skills, priming, and simple forms of memories. One example of an implicit type of memory is procedural memory, which guides the execution of skills and tasks without conscious retrieval. These memories include tying shoes, riding a bike, driving a car, skiing, playing the piano, etc. Procedural memories are stored long term through a learning phase characterized by many repetitions while all the relevant neural systems work together to produce the action automatically. Implicit procedural learning is essential for developing any motor skill, and the brain regions involved in forming and storing these memories include the striatum, basal ganglia, cerebellum, and limbic system.10 Implicit memories, once established as long-term representations, can last a lifetime. As for the explicit types of memory, the biological underpinning of this very long-lasting memory storage is not yet understood."
We have here some examples of the tricks discussed in my bullet list above. Psychology references having nothing to do with neural explanations for memory are mixed up with some specific references to brain anatomy, without any mention of how such brain anatomy can explain such phenomena. We have claims of brain memory storage, which have no specifics of how such a thing could occur: "Procedural memories are stored long term through a learning phase characterized by many repetitions while all the relevant neural systems work together to produce the action automatically." That is the vaguest hand-waving. In the underlined phrases, we have confessions that neuroscientists do not actually have any understanding of how long-lasting memory storage can occur. It makes no sense for someone to be confidently asserting (as Alberini does in the quote above) that brains store memories, and also to confess as she does that we do not understand how long-term memory storage occurs. If you do not understand how long-term memory storage occurs, you should have no confidence that brains store memories, particularly given that short-term memory storage is also not understood.
Alberini then makes these faulty claims, which involve falsehood, bluffing and speculation:
"Long-term memories do not form instantly upon learning. They are initially fragile, and, in fact, in their early phase, they can be disrupted relatively easily by biological, pharmacological, or behavioral interference. However, over time, or via repeated learning, they build strength and become resistant to disruption through a process known as memory consolidation—a collection of biological changes taking place in several brain regions of the relevant memory system, which may include experience repetitions or reactivations, and eventually result in long-lasting, stable representations."
The first sentence is untrue. Many long-term memories do form instantly upon learning. If you are told of the death of your child or the death of your parent, you will instantly form a permanent new memory for the rest of your life. You do not need repeated notifications of such a death before the memory becomes permanent. The claim that you do not learn something until repeated exposures to it is untrue. Anyone can learn the plot of a movie by watching it a single time, and he may remember that plot for years, even though he has only seen the movie once. Learning something might require repeated exposures, but it very often does not. Scientists define a long-term memory as anything you remember for days or longer. Even many not-very-interesting things can be added to long-term memory after a single sensory experience. I often remember trivial little things I read about or experienced days, weeks, months or years ago, even if I never thought about such things between the time I read or experienced them and the time I remembered them. So neuroscientists deceive us when they make some generalization that learning requires multiple exposures.
Why do neuroscientists make obviously false claims like those in the quote above? It is because the reality of instant learning is one that defies all claims that learning occurs through brain mechanisms. The brain has nothing like any component that could account for the instant learning that so commonly occurs in a person's life. When neuroscientists speculate about how memory formation could occur, they speculate about sluggish, very slow processes such as protein synthesis, which would require many minutes. So for neuroscientists, the reality of instant learning is a scandal they must sweep under the rug, by telling us deceits such as the deceit that learning requires multiple sensory exposures.
Alberini is bluffing when she makes the vague hand-waving statements below, speaking as if she knows things she does not really know:
"Memory storage refers to the process of holding the learned information. When needed, memories are recalled or retrieved, and this process can temporarily return the memory to a labile state, during which the memory restabilizes—a process known as memory reconsolidation. Each of these memory processes requires the contributions of multiple brain regions, cell populations, and biological pathways that become activated and functionally engaged following learning and evolve over time."
These "sound like I understand things" claims are contradicted by her previous confession: "As for the explicit types of memory, the biological underpinning of this very long-lasting memory storage is not yet understood." "Labile" means "easily altered." There is no evidence that recalling or retrieving a memory causes a memory to become "labile." To the contrary, verbally recalling a memory will make it less likely to be forgotten.
In the quote below, Alberini asks some good questions, which she follows with a false boast that is the opposite of the truth:
"What mechanisms underlie the formation and storage of memory? Are the biological mechanisms recruited to form and store different types of memories similar or different? Where do they occur? How can they explain memory storage that lasts for a lifetime? Are they different at different ages? What mechanisms underlie memory recall? And so on. Over these 40 years, monumental progress has been made."
No, the truth is that no progress has been made in answering these questions. No claims of such progress will hold up to critical scrutiny. Typical claims of progress involve appeals to poorly-designed junk science studies such as rodent studies using way-too-small study group sizes and a bad, unreliable "freezing behavior" method for judging how well a rodent remembered.
The Figure 1 of Alberini's paper is a laughable visual. She has taken a "double bullet list" approach. We have a picture of a brain, with the word "Memory" superimposed over it. On the left of this picture is a bullet list of neuroscience terms, referring to parts of the brain or chemical processes of the brain. On the right of this picture is another bullet list of neuroscience terms, referring to other parts of the brain or chemical processes of the brain. The figure has arrows pointing from these bullet lists to the picture of the brain. Bullet lists are not explanations. None of the items listed in the bullet list do anything substantive to explain how a human could form a memory, preserve a memory or instantly recall a memory.
Alberini makes the untrue claim here: "Far from being just glue or filler cells, astrocytes have been shown by numerous studies to actively contribute to learning and memory through several mechanisms (Figure 2)." The Figure 2 claims that astrocytes do "computing, encoding and storing information." There is no good evidence that any part of the brain does any such thing as encoding memories or storing learned information. No neuroscientist has any credible tale to tell of how any brain component could do such things, and microscopic examination of brain tissue always fails to provide any evidence that such things occur in the brain. with not a single speck of learned information ever being found through microscopic examination. Alberini makes the untrue claim that "recent findings provided compelling evidence for the direct roles of astrocytes, similar to those played by neurons, in computing, encoding, and storing information."
Here are some examples of the bad studies she cites to try and back up such boasts:
- "Lactate produced by glycogenolysis in astrocytes regulates memory processing." This is a junk science rodent study using way-too-small study group sizes much smaller than 15, and usually much smaller than 10.
- "Lactate from astrocytes fuels learning-induced mRNA translation in excitatory and inhibitory neurons." This is another junk science rodent study using way-too-small study group sizes much smaller than 15, and usually much smaller than 10.
- "Astrocyte-Neuron Lactate Transport Is Required for Long-Term Memory Formation." This is another junk science rodent study using a way-too-small study group size of only 7 mice.
- "Astrocytic β2 Adrenergic Receptor Gene Deletion Affects Memory in Aged Mice." This is another junk science rodent study using a way-too-small study group sizes such as only 3, 5 and 6.
These are the results of my examination of a random selection of four papers that Alberini claims as evidence that astrocytes have something to do with memory. We may guess that the other studies she claims are equally bad examples of low-quality neuroscience.
As a general rule, we should not trust the generalizations that neuroscientists make about human mental performance, because neuroscientists have a long history of mischaracterizing the mental abilities of humans, by making human minds sound much more weakly-performing than they are, so that neuroscientist explanations sound less far-fetched. As an antidote to such mischaracterizations, remember the facts of your own mental abilities, and also study the very important topic of human best mental performances. A study of human best mental performances will typically blast into smithereens the type of generalizations that neuroscientists like to make about how human minds perform. You can find many posts about human best mental performances by reading posts like the ones available at the links below:
- exceptional auditory memory
- exceptional language ability
- exceptional mathematics ability
- exceptional memory
- exceptional multitasking
- exceptional musical memory
- exceptional reading ability
- exceptional recall of facts
- exceptional recall of number sequences
- exceptional recall of text sequences
- exceptional recognition memory
- exceptional speed of memorization
- exceptional speed of thinking
- exceptional time-related ability
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